The how to shift trucks thread

[Truck Shop]

RND is my favorite shift pattern.

You need to venture out.

 

[Birken Vogt]

RND is my favorite shift pattern.

As long as Allison makes a transmission I could care less how to double clutch and split gears. All I need a truck to do in the dirt business is get from point A to point B safely and efficiently with the occasional on-site use so an auto fits the bill for us.

Maybe in the flats, but in these mountains there are two more buttons on the display, up and down. If you care about your brakes you are up pushing those buttons as often as moving a shift lever almost. The difference is it doesn't miss shifts as often or grind any gears.

Myself, I just drive whatever I am given.

 

[kshansen]

I worked on a bunch of Mack Quadrplex transmissions over the years and a few Triplex transmissions. Most of the time I never got to do a test drive as they were often sent to another plant somewhere in the state to be installed. Most all of these were off-highway dump trucks so in a way having all those gears was some of a waste as most never saw 25 mph!

One thing I remember is going for with a guy after I had fixed a fuel line problem on the tractor he hauled stone trailers over the highway on everything from crowded city streets Interstate Highways. I got a kick out of how easy he made it look. Nothing rushed or fancy driving with two hands working the levers with arm looped through the steering wheel. All this while carrying on a relaxed conversation! If I didn't know better I would have thought to levers were not really hooked to anything and it really had an Allison automatic behind that diesel! Then again an Allison would not been that smooth!

 

[CM1995]

You need to venture out.

Nah - I''ll pass.

Maybe in the flats, but in these mountains there are two more buttons on the display, up and down. If you care about your brakes you are up pushing those buttons as often as moving a shift lever almost. The difference is it doesn't miss shifts as often or grind any gears.

Myself, I just drive whatever I am given.

We don't have mountains like ya'll out west but we have hills with valleys and an endless supply of traffic shoved into roads that should've been upgraded years ago. I'll take an Allison 6sp behind a pre-emission MP7 any day and all day for what we do.

The auto's I've owned worked well with the retarder and jake brake for our conditions.

 

[Birken Vogt]

For vocational trucks I think Allisons seem like a money saver. No clutches to wear out, shift forks to get worn or bent by rough drivers, or whatever goes wrong with a crash box. There is a reason they put hyd wet clutch based transmissions in graders and bulldozers and not manual clutches and shift rail transmissions.

 

[JaredV]

Everyone has heard the cowboys that shift blapping the Jake between gears, empty on flat ground hitting every gear, but how many know know how to shift by cutting off the Jake? I discovered this by accident with an 18 speed. I was going downhill in direct with the Jake on and didn't realize I had the splitter in over (yeah I know). When I got to the bottom and cut it off, it shifted. I think the torque in the drivetrain is wound up like a spring just a little, just enough to throw some slack into the transmission to slip it out of gear. Now I use it all the time when descending a hill slower than the speed limit and I want to let it roll when almost to the the bottom. Cut the Jake, slip it out and grab the next gear. I've done it with 3406Es, C15s and one BC 350. Some didn't want to do it if the fan was on or if the rpms weren't between like 11 and 1800 or something like that. Some like the C15 that I drive now is pretty reliable. I've asked a number of drivers if they knew about it and none had.

 

[chidog]

I had that 2 spd down to a science. I liked my loop gear I called it since a normal progression through that 5 speed was not the right split , don't remember which gears though, its been a long time. Many times when I drove most trucks I'd pull it out of gear like floating shifts and clutch into the next gear like a double clutch.

 

[chidog]

For vocational trucks I think Allisons seem like a money saver. No clutches to wear out, shift forks to get worn or bent by rough drivers, or whatever goes wrong with a crash box. There is a reason they put hyd wet clutch based transmissions in graders and bulldozers and not manual clutches and shift rail transmissions.

"No clutches to wear out", Allisons are full of clutches, and they do wear out on occasion. Same with the Cat power shift transmissions, especially if there is a low oil pressure problem some place.

 

[DMiller]

"No clutches to wear out", Allisons are full of clutches, and they do wear out on occasion. Same with the Cat power shift transmissions, especially if there is a low oil pressure problem some place.

Pretty much what was gonna add. Thanks for that.

 

[Truck Shop]

"No clutches to wear out", Allisons are full of clutches, and they do wear out on occasion. Same with the Cat power shift transmissions, especially if there is a low oil pressure problem some place.

It was pretty rare to see a OTR with a Allison-too much extra weight coupled with high fuel consumption.
A Greyhound with a smelly two stroke and a Allison got about 3.5 at best, terrible combination despite what
some think.
It's the reason for automated manual transmissions today. Lighter no converter no extra places to leak and
way more gear ratios. On todays AMT's in auto mode it can be driven through towns/urban areas stop light
after stop light left in jake mode will down shift using jake to under 10 mph without touching the brake until
needed to bring to a stop. But getting a driver to operate it that way is another matter.

 

[Old Doug]

For vocational trucks I think Allisons seem like a money saver. No clutches to wear out, shift forks to get worn or bent by rough drivers, or whatever goes wrong with a crash box. There is a reason they put hyd wet clutch based transmissions in graders and bulldozers and not manual clutches and shift rail transmissions.

There is a place were a automatic is the only way to go . I rebuilt alot of automatics in the 80s and 90s . One thing in a 4x4 pickup it wasnt any cheaper than a stick most didnt understand how to and when the trans saver need to be used. With a stick it was easy to tell what was going on and when a lower gear was needed. My biggest deal with a automatic is trust . My Jeep had $2000.00 spent on its trans before i got it and it seems to do stuff it shouldnt once in a while . I dont want to shift gears in my car but i dont plan on having a automatic in my pickup.

 

[cfherrman]

If you buy a 4x4 diesel pickup 2000 ish + it has to be an auto or your severely limiting your off road capability. Brake boosting to 20 psi helps a lot to get un-stuck.

As far as autos in big trucks, I don't like driving the folders ones down the road like the 750's as they don't brake enough, they will when you put them in like 2-3 and your going slow enough. The new Allisons like the 4500 with a vgt turbo are a dream to drive. Just out it in 6 and drive like it's a pickup, turn on the turbine brake and it slows down for you and downshifts. The turbine brake is quiet so leave it on everywhere.

I've driven a few manuals with turbine brakes and it's much nicer than the old Jake but I find lower than 55 mph it's much easier to catch gears and slow down with a Jake if I'm trying to not use the brakes at all. Still rather have the turbine brake as it's just software and much simpler than a Jake.

 

[Spud_Monkey]

 

[DMiller]

Only drove one cat with a retarder, never quite got used to it before went back to owner. Seemed a good thought as to using essentially a torque converter style system to retard a load.

 

[Spud_Monkey]

Personally speaking I noticed the automatics seem to be hesitant of wanting to move till you give it some good throttle. It's as if there is a brake dragging somewhere from what I have seen. Barely blip the throttle on a manual in a low gear and it moves freely.

 

[CM1995]

Personally speaking I noticed the automatics seem to be hesitant of wanting to move till you give it some good throttle. It's as if there is a brake dragging somewhere from what I have seen. Barely blip the throttle on a manual in a low gear and it moves freely.

Think it depends on the transmission. Had an '07 Mack with 4560 in it that would leave cars at the red light unloaded. That truck was a dream to drive. Throw a 315 on the tag trailer and cruise the interstate at 75 all day long.

 

[Birken Vogt]

"No clutches to wear out", Allisons are full of clutches, and they do wear out on occasion. Same with the Cat power shift transmissions, especially if there is a low oil pressure problem some place.

I know Allisons are full of clutches but I can't say we ever had a problem with the modern World series except one lost an ECM once. Trucks ran their entire lifetime with nothing but an occasional oil change, Transynd oil change intervals with Prognostics are ridiculously long also, don't tell Mike.

Manuals in vocation service are often in the shop having one thing or another repaired. Nothing catastrophic, just more trips in.

 

[Truck Shop]

Transynd oil change intervals with Prognostics are ridiculously long also, don't tell Mike.

250,000 on amt's.

Personally speaking I noticed the automatics seem to be hesitant of wanting to move till you give it some good throttle. It's as if there is a brake dragging somewhere from what I have seen. Barely blip the throttle on a manual in a low gear and it moves freely.

Depends on the amt, the DT12 is more responsive than the Eaton.

 

[shopguy]

Manual transmissions may make a comeback now that we have hands free phones,won’t have to stop complaining to shift

 

[56wrench]

Most of us old guys that grew up on a farm learned to drive a 2 spd axle equipped truck when we were quite young. Anything after that was easy